﻿using System;
using System.Linq;
using System.Collections.Generic;

/* Copyright (c) 2010 CBaxter
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), 
 * to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, 
 * and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 
 * IN THE SOFTWARE. 
 */

namespace Xpedite.Resources.Compressors
{
  internal interface ICompressor
  {
    Boolean HasContentEncoding { get; }
    String ContentEncoding { get; }

    Byte[] Compress(Byte[] bytes);
  }

  internal interface ICompressorFactory
  {
    ICompressor Create(String acceptEncoding);
  }

  internal class CompressorFactory : ICompressorFactory
  {
    private readonly IDictionary<String, AcceptEncodingHeader> _acceptEncodings = new Dictionary<String, AcceptEncodingHeader>();

    internal IEnumerable<AcceptEncodingHeader> ParsedAcceptEncodings { get { return _acceptEncodings.Select(item => item.Value); } }

    public ICompressor Create(String acceptEncoding)
    {
      AcceptEncodingHeader parsedHeader;

      lock (_acceptEncodings)
      {
        if (!_acceptEncodings.TryGetValue(acceptEncoding, out parsedHeader))
          _acceptEncodings.Add(acceptEncoding, parsedHeader = AcceptEncodingHeader.Parse(acceptEncoding));
      }

      if (parsedHeader.GetAcceptEncodingQualityFor(AcceptEncodings.GZip) > 0)
        return new GZipCompressor();

      if (parsedHeader.GetAcceptEncodingQualityFor(AcceptEncodings.Deflate) > 0)
        return new DeflateCompressor();

      return new DefaultCompressor();
    }
  }
}
